Swing check valves have a simple operation

A swing check valve, also called a flap valve or tilting-disc check valve, has a hinged disc that allows fluid to flow in one direction and automatically closes to prevent backflow. These valves can be used on liquid or gas services and are typically found in industrial applications such as wastewater and steam. They can be installed in either horizontal or vertical orientation and are suitable for both high and low pressures.

Swing check valves have a simple operation. As the fluid pressure in the piping system rises, it forces the door of the valve open and allows the flow to pass through. When the flow is reversed, the force of the fluid will push the door shut against the seat. When the valve is installed correctly, it opens only when the flow is in the desired direction.

These valves are typically made of cast iron, stainless steel or bronze and have a long life when properly maintained. They are often lubricated with a light mineral oil. When the valves are not in use, they should be stored in a dry, ventilated area to avoid moisture and rust.

When maintenance is required, the valve should be removed from service and cleaned by flushing with clean water or solvent to remove any debris or contaminants. In addition, the valve should be inspected for corrosion, wear and any signs of leakage. During the inspection, any components that are worn should be replaced to ensure proper sealing of the valve.

Unlike wafer check valves, which have a butterfly or “wafer” style disc on a spring that allows the disc to float when inlet pressure overcomes cracking pressure, swing check valves are designed with a straight body and a seat that is integral with the body. This design means that there is no place for debris or contaminants to build up and cause leaks. The straight body design also makes it easier for maintenance technicians to inspect the interior of the valve.

In order for a swing check valve to operate, the disc must be completely clear of obstructions. If the valve has a single-disc, it must be installed so that the opening of the valve is directly ahead of the seat. Double-disc swing check valves, on the other hand, can be installed with the opening of the valve behind the seat.

Swing check valves are a reliable solution for blocking backflow in most applications, but they can create problems when installed in the wrong orientation. In these instances, it is important to understand how the valve works in order to avoid any issues. Silent check valves, which have a spring-loaded disc that travels a short distance along the axis of the pipe & closes within a fraction of a second, are an excellent option for reducing noise and water hammer in installations where swing check valves can’t keep up with the speed of the fluid.